PhD Thesis abstract published online as a service to the JDR Community.
Assessment of udder morphophysiological characteristics and dairy potentialities of the Sicilo-Sarde ewe in Tunisia for a better adaptation to mechanical milking
Rafik Aloulou
Rafik Aloulou
Abstract
This thesis aims to study the ability of Sicilo-Sarde ewes to machine milking and the effect of livestock management (lactation/weaning/milking) on their dairy potentialities during lactation, in order to identify the best ways to optimize them. Three methods (measurement, notation, digital photos) and two technics (ultrasound, hormonal) were used to study the external and internal udder morphology, respectively. Quantitative and qualitative dairy performances during lactation (suckling and exclusive milking period) were compared according to three weaning modalities and two suckling types for two different mating seasons. The udder of the Sicilo-Sarde ewes seemed to have a small depth, a developed cistern and very horizontal teats. Such characteristics compromise its ability to machine milking in spite of some others good traits such as equilibrated half-udders, a well attached udder and uniform shape and size of teats. The Sicilo-Sarde ewes showed a good milk potential during the suckling period, higher than that usually obtained during the milking period, with a good growth rate of lambs during their two first months of age. The practice of an early semi-weaning (mixed suckling/milking) at six/seven weeks of lamb age is still possible, and even recommended. It allows an increase of the commercialized milk quantity. The proportion of residual milk remains too important, resulting in a bad udder stimulation and therefore in an insufficient udder emptying, which needs the improvement of milking conditions. For a better breed valorization, a well-adapted and concerted selection scheme implicating all engaged actors and taking into account firstly the classical dairy traits and then other topics such as milking speed and efficiency is to be established. The successful outcome of such a selection schema depends, among others, on urgent adjustments to the level of current milking management in order to make it more appropriate to the breed specialization in milk production (earlier weaning associated to a mixed suckling/milking period).
This thesis aims to study the ability of Sicilo-Sarde ewes to machine milking and the effect of livestock management (lactation/weaning/milking) on their dairy potentialities during lactation, in order to identify the best ways to optimize them. Three methods (measurement, notation, digital photos) and two technics (ultrasound, hormonal) were used to study the external and internal udder morphology, respectively. Quantitative and qualitative dairy performances during lactation (suckling and exclusive milking period) were compared according to three weaning modalities and two suckling types for two different mating seasons. The udder of the Sicilo-Sarde ewes seemed to have a small depth, a developed cistern and very horizontal teats. Such characteristics compromise its ability to machine milking in spite of some others good traits such as equilibrated half-udders, a well attached udder and uniform shape and size of teats. The Sicilo-Sarde ewes showed a good milk potential during the suckling period, higher than that usually obtained during the milking period, with a good growth rate of lambs during their two first months of age. The practice of an early semi-weaning (mixed suckling/milking) at six/seven weeks of lamb age is still possible, and even recommended. It allows an increase of the commercialized milk quantity. The proportion of residual milk remains too important, resulting in a bad udder stimulation and therefore in an insufficient udder emptying, which needs the improvement of milking conditions. For a better breed valorization, a well-adapted and concerted selection scheme implicating all engaged actors and taking into account firstly the classical dairy traits and then other topics such as milking speed and efficiency is to be established. The successful outcome of such a selection schema depends, among others, on urgent adjustments to the level of current milking management in order to make it more appropriate to the breed specialization in milk production (earlier weaning associated to a mixed suckling/milking period).
Affiliation and Awarding Institution: Université de Sousse, Institut Supérieur Agronomique de Chott-Mariem, Sousse, Tunisie.
Corresponding E-mail address: [email protected]
Availability of full Thesis: please contact author
Corresponding E-mail address: [email protected]
Availability of full Thesis: please contact author
Abstract published 21 January 2021.
